CVE-2019-20478: In ruamel.yaml through 0.16.7, the load method allows remote code execution if the application calls this meth

Q: How do I fix CVE-2019-20478?

ruamel.yaml: upgrade to newer than 0.16.7. Exact commands for each OS are on this page.

Q: Is CVE-2019-20478 being exploited?

CVE-2019-20478 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2019-20478 affect?

CVE-2019-20478 affects ruamel.yaml. Severity is critical (CVSS 9.8). In ruamel.yaml through 0.16.7, the load method allows remote code execution if the application calls this method with an untrusted argument. In other words, this issue affects developers who are unaware of the need to use methods such as sa

Q: How urgent is CVE-2019-20478?

Priority 63/100. Critical severity; EPSS top 6%: very likely to be exploited; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2019-20478 is a critical-severity flaw (CVSS 9.8) affecting ruamel.yaml. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In ruamel.yaml through 0.16.7, the load method allows remote code execution if the application calls this method with an untrusted argument. In other words, this issue affects developers who are unaware of the need to use methods such as safe_load in these use cases.

Why this priority

Critical severity
EPSS top 6%: very likely to be exploited
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	6.8% (top 6%)
CISA exploited list	No
Published	2020-02-19
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: ruamel.yaml project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-02-19 04:15 UTCPublished CVE record published
2026-06-17 02:30 UTCUpdated Record last modified

ruamel.yaml project ruamel.yaml UPGRADE

Affected: <= 0.16.7

Fixed in: newer than 0.16.7

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ruamel.yaml || rpm -q ruamel.yaml || ruamel.yaml --version

2. UPGRADE to newer than 0.16.7 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade ruamel.yaml

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade ruamel.yaml

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2019-20478?

ruamel.yaml: upgrade to newer than 0.16.7. Exact commands for each OS are on this page.

Is CVE-2019-20478 being exploited?

CVE-2019-20478 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2019-20478 affect?

CVE-2019-20478 affects ruamel.yaml. Severity is critical (CVSS 9.8). In ruamel.yaml through 0.16.7, the load method allows remote code execution if the application calls this method with an untrusted argument. In other words, this issue affects developers who are unaware of the need to use methods such as sa

How urgent is CVE-2019-20478?

Priority 63/100. Critical severity; EPSS top 6%: very likely to be exploited; Remotely exploitable, no login, no user action

References

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